(the title of this post hearkens back to a small book / card which Warren Chappell created, “Let’s make a “B” for Bennet” — I was fortunate to meet Mr. Chappell when he was Artist-in-Residence at UVA on a school field trip when I was young, and he was the author, along with his cousin Oscar Ogg, of a number of books I remember from my youth.)

Okay, step-by-step, hopefully correct this time.

Start by launching Carbide Create — set the width of the drawing area to 20", the height to 15", OK

Ensure the grid spacing is 0.50 — screen appearance should be (we’re using Imperial 'cause that’s what I grew up with, and I haven’t yet brought myself to replace my favourite four-fold rule with a metric one — if someone has a spare $400 you can buy it from Jim Bode Tools and send it my way)

Note that one must click on the beginning point a second time so as to close the path, clicking “Done” instead of doing so will result in an open path which can only be used for Toolpath | Contour | No Offset toolpaths

Select the diamond, then select the “Curve Edit Mode” (third edit mode on the far right — it may be necessary to select “Node Edit Mode” (the one in the middle) first):

Point to the top node, it should highlight black, then click, hold the mouse button down, and while holding, drag to the left or right (the necessary direction will depend on the order in which the nodes were clicked originally — most drawing programs expect the same winding rule as PostScript, left-hand fill — fill is towards the left-hand side of the path — the diamond points should have been clicked in counter-clockwise order, and one should drag to the left) until one gets to the point in the background — release the mouse to achieve:

Repeat this process until one has:

Targeting the nodes is a bit tricky, and I find the (occasional? bug?) need to click on Node Edit Mode first a bit odd. It may be on a high-resolution screen that the nodes are very small and difficult to target — unfortunately, Carbide Create lacks an option for setting a number of pixels to relax this targeting, nor to afford the user control over the size at which such selected node highlights are drawn. If you have any difficulties with this, please contact support@carbide3d.com and we will see what can be done.

it looked different somehow but I found it.
I imported the DXF and traced it with poly lines. not sure if that step was needed, then used the curve tool to somewhat copy the ellipse from acad…
It would be easier for carbide create to just give an ellipse…